Efficiency, Differential Temperature and Noise
Efficiency is defined by the power output divided by the power input and is usually expressed as a percentage. If a PSU were a 100% efficient (which none are) 700 watts of AC power going in would result in 700 watts of DC power coming out (with no waste heat to dissipate). In the real world there are always inefficiencies and power is lost in the form of heat during the conversion process. Newer revisions to the ATX12V Power Supply Design Guide V 2.2 have continued to increase the efficiency recommendations for PC switching mode power supplies and now lists both required and recommended minimum efficiencies.
We measured the AC power input to the SilverStone SX700-LPT with an Extech power analyzer while the total DC load was found by adding all the individual +3.3V, +5V, +12V, -12V and +5VSB loads together.
The overall efficiency of the SilverStone SX700-LPT power supply is excellent and easily meets the 80 Plus Platinum guidelines, even when operating on 120VAC and at elevated temperatures. Notice how relatively flat the efficiency curve is, showing the PSU is operating very efficiently over a wide range of loads.
80 Plus Program
Note: Tests conducted at room temperature (25°C)
Differential Temperature and Noise Levels
To simulate a demanding environment, some of the warm exhaust air from the PSU under test is recirculated back to the intake through a passive air duct, which allows the PSU air inlet temperature to increase with load, up to 40°C.
The differential temperature across the power supply was calculated by subtracting the internal case air temperature (T in) from the temperature of the warm exhaust air flowing out the back of the power supply (T out).
Thermocouples were placed at the air inlet and exhaust outlet. The ambient room air temperature was 23ºC (74ºF) +/- 0.5ºC during testing.
T out = temperature of air exhausting from power supply
T in = temperature of air entering power supply
Delta T = T out – T in
Sound pressure level readings were taken 3’ away from the rear of the case in an otherwise quiet room. The ambient noise level was ~28 dBA.
Note: Fan not spinning in Zero RPM Mode*
The SX700-LPT power supply starts out in Zero RPM fan mode and is dead silent. The fan started spinning once we hit the 50% load test and stayed very quiet through mid-power range. At full load with an elevated ambient temperature, the cooling fan did speed up and the noise became noticeable but never became really loud.
(Courtesy of SilverStone)
SFX-L seems like such a
SFX-L seems like such a pointless standard, you can get SFX PSUs at 600W, no small system is gonna pull more power than that.
First off, they clearly laid
First off, they clearly laid out the advantages of having a 120mm fan for lower noise.
You also lack imagination. SFX and SFX-L now make ATX sized units seem ridiculously big and unnecessary. Silverstone is coming out with a 800W 80+ Titanium rated SFX-L unit later on this year that could power an overclocked HEDT processor and dual Titan X rig easily (a lot of people over estimate the power needs for a system by a lot).
I have an R9 Nano in an SFF
I have an R9 Nano in an SFF build which has a recommended PSU of 750W.
I bought this PSU for that build. It does just fine, even when the GPU and CPU (which is a 6600K) are both overclocked.
The 450W PSU which I had with the case originally wasn’t enough for the GPU at peak load, let alone with a 95W TDP CPU + overclock. It had two 12V rails. This has one 12V rail with 58A. More than enough.
There’s nothing wrong with meeting the recommended specs *and* having some additional headroom.
i will be running 2x gtx 1080
i will be running 2x gtx 1080 hybrids off one of these with a i7-6700k all overclocked using every drop of power this thing has to offer
A gem of a review once again.
A gem of a review once again. Why did Silverstone only put a 3 year warranty on this? That makes no sense. It should indeed have at least an 5 year warranty.
I would advise caution when
I would advise caution when buying this PSU do to quality control. I bought one off Amazon for my ITX build, but the PSU would randomly shut off as if the power cord was unplugged. This would happen at random times like while installing Windows, watching Youtube, or just idling. I would have to unplug the power cord from the PSU to be able to restart my PC.
I returned it and bought the SX500-LG and so far it has worked perfectly.
I’m not saying you’re wrong.
I’m not saying you’re wrong. I’m just saying that one faulty OCP circuit does not indicate a QC problem, it indicates one faulty OCP circuit.
There’s a lot of that
There’s a lot of that happening, people are complaining on forums and reviews on neweeg.ca points that same issue, which is very sad. To be fair my corsair sf600 is having the same issues,It has to do with power surges.
There is a bug with the
There is a bug with the semi-fanless mode on the SX700-LPT: The fanless mode is triggered by dropping below a certain power draw only, rather than by power and/or temperature. But the unit still has overtemp protection. This means if the unit is heated up while under low-load conditions, it can become warm enough to trigger overtemp shutdown without the fan ever kicking in!
Whether this is an issue depends on PSU orientation (opening-down = bad), inlet restriction (e.g. fan filters), case airflow (if any), and ambient temperature.